Angular Velocity of a Nebula Accretion Disk

[SOLVED]
According to astronomy our solar system was created about 4.5 billion years ago when the nebula of an exploded supernova accreted to form a stellar mass known as our sun.

They say that this "accretion disk" or mass of clumping particles spun around due to its angular velocity.
Now I ask you how did those particles attain an angular velocity?

It's not like gravity pulls side ways. If there's a 3D field of gas and dust suspended in space, the particles clump together very slowly because of the fundamental gravitational force. somewhere in the center it starts to become dense and then even more particles move there.

Correct me if I'm wrong but gravity dosen't pull sideways, it pulls inward towards the largest collection of mass, just like here on earth, I'm being pulled on the y axis.

There has to be something I'm missing that causes this particle disk to spin.